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Abstract:

System and Method is described that slows the release of contaminated
water by rapidly freezing the ground water, including salt water, which
permeates the area underneath the a contamination source such as a melted
reactor, so that the resulting ice lens mitigates the extent to which
radioactive water is released into the environment. The method here
described may be used for this purpose through the accomplishment of two
goals; first, a resulting reduction in the quantum of radioactive water
released, per se, and secondly, a reduction in the level of particulate
radiation reaching the environment due to slowed water flow velocities.
Cooling channels in thermal contact with the water and soil evaporate a
low boiling point liquid in order to cool the proximate water and soil.
The low boiling point liquid is supplied by an insulated supply channel.
The channels are bored into the earth using known boring/tunneling
techniques.

Claims:

1. A method of restricting the migration of contaminated ground water
surrounding a contamination source, comprising: boring a plurality of
vapor exhaust channels to form a containment grid in the ground proximate
and underneath the contamination source, said vapor exhaust channels in
thermal communication with the ground surrounding the exhaust channels,
boring one or more gas delivery channels said one or more gas delivery
channels thermally insulated from the ground surrounding the one or more
gas delivery channels, said plurality of vapor exhaust channels being in
fluid communication with at least one of the one or more gas delivery
channels, providing a low boiling point liquid through the one or more
gas delivery channels to the plurality of vapor exhaust channels and
evaporating the liquid in the vapor exhaust channels to extract heat from
the ground surrounding the exhaust channel to cool or freeze the ground
water proximate the vapor exhaust channels to thereby restrict migration
of contaminated ground water surrounding the contamination source.

2. The method of claim 1, wherein the steps of boring a plurality of
vapor exhaust channels and boring one or more gas delivery channels
further comprises micro-tunneling.

3. The method of claim 1, wherein the steps of boring a plurality of
vapor exhaust channels and boring one or more gas delivery channels
further comprises direct jacking.

4. The method of claim 1, wherein the low boiling point liquid is
nitrogen

5. The method of claim 1, wherein the low boiling point liquid is
ammonia.

6. The method of claim 1, wherein the low boiling point liquid is Freon.

7. The method of claim 1, wherein each of the plurality of vapor exhaust
channels is associated with one of the one or more gas delivery channels.

8. The method of claim 1, wherein the evaporated liquid is condensed and
returned to the vapor exhaust channels via the one or more gas delivery
channels.

9. The method of claim 1, wherein the plurality of vapor exhaust channels
and the gas delivery channels are separated by a restrictive aperture.

10. A method of protecting a water table from a nuclear meltdown
comprising: forming a containment grid in the water table proximate a
contamination source with a plurality of cooling channels in thermal
communication with the water and soil in proximity to the cooling
channels and in fluid communication with an insulated supply channel;
forcing a low boiling point liquid into the plurality of cooling channels
via the insulated supply channel; and, evaporating the low boiling point
liquid with heat drawn from the water and soil in proximity to the
cooling to thereby retard water movement from the containment grid.

11. The method of claim 10, wherein the plurality of cooling channels are
pipes inserted into bored channels.

13. The method of claim 12, wherein at least one of the cooling channels
and insulated supply channels share the same bored channel.

14. A containment system for preventing the migration of fluid from a
contaminate source comprising: a containment grid comprising a plurality
of cooling channels, said grid defining a plurality of regions between
adjacent cooling channels; an aggregate comprising frozen water and soil,
said aggregate in thermal communication with the plurality of cooling
channels and occupying the regions between adjacent cooling channels; a
supply channel thermally insulated from the aggregate; said supply
channel containing a low boiling point liquid and in fluid communication
with said cooling channels; and, said cooling channels containing vapor
evaporated from the low boiling point liquid; wherein said containment
grid forms a partial envelope around the contaminate source beneath the
ground surface.

15. The system of claim 14, wherein the partial envelope comprises a
substantially ally inclined portion and a substantially lateral portion.

16. The system of claim 14, wherein the partial envelope is shaped as a
upright bowl.

17. The system of claim 14, further comprising a compressor system in
fluid communication with the cooling channels and the supply channel,
wherein the vapor is compressed into the low boiling point liquid and
provided to the supply channel.

Description:

CROSS REFERENCES

[0001] This non-provisional application claims priority benefit of
co-pending Provisional application No. 61/471,967 filed Apr. 5, 2011
entitled "Rankine Cycle Ice-Lens Formation With Secondary Cupping as a
Meltdown Mitigation Technique in a Water Table," the entirety of which is
hereby incorporated by reference.

BACKGROUND

[0002] The disclosed subject matter is directed to a System and Method for
retarding the speed of flow of contaminated water, from a nuclear reactor
or other contamination source from which such contaminated water is
issuing.

[0003] The subject matter uses micro-tunneling, coupled with pipe
insertion, coupled with insulated pipe insertion, so that liquids with
very low boil points, such as Liquid Nitrogen, or other refrigerant
gasses, may be inserted in the liquid state, to vaporize upon release
from the insulated containment, so that heat energy is absorbed from the
water table, resulting in a reduction in flow rate, thereby impeding the
capacity of the water under flow to carry particulate matter.

[0004] The subject matter also discloses a "laced" approach, in which twin
barreled pipes, as herein set forth, may be inserted an non-conflicting
depths, but in such proximity to mutually contribute to water sludge
accumulation, ice rime, and, with sufficient evaporation process, the
formation of an ice lens, sufficient to retard the escape of contaminated
water.

[0005] The effect of this System and Method is to slow the release of
contaminated water as it is possible to rapidly obtain the freezing the
ground water, including salt water, which permeates the area underneath
the melted reactors, so that the resulting ice lens will mitigate the
extent to which radioactive water is released into the environment. The
method here described may be used for this purpose through the
accomplishment of two goals; first, a resulting reduction in the quantum
of radioactive water released, per se, and secondly, a reduction in the
level of particulate radiation reaching the environment due to slowed
water flow velocities.

[0006] It is advantageous to appreciate the existence of "trenchless
excavation" for pipe installation. "Direct Jacking," and the
"Micro-tunneling" are approaches widely deployed in the civil engineering
context, and similar approaches are used for waste water treatment pipe
installation.

[0007] Direct Jacking is a tunneling process whereby a single new pipe is
installed in one pass. A bore head begins the tunnel excavation from an
access shaft and is pushed along by hydraulic jacks that remain in the
shaft. The link to the boring head is maintained by adding jacking pipe
between the jacks and the head. By this procedure, the pipe is laid as
the tunnel is bored.

[0008] Micro-tunneling is defined as a trenchless construction method for
installing pipelines. The North American definition of microtunneling
describes a method and does not impose size limitations on such method;
therefore, a tunnel may be considered a microtunnel if all of the
following features apply to construction:

[0009] Remote Controlled: The microtunneling boring machine (MTBM) is
operated from a control panel, normally located on the surface. The
system simultaneously installs pipe as spoil is excavated and removed.
Personnel entry is not required for routine operations.

[0010] Guided: The guidance system usually references a laser beam
projected onto a target in the MTBM, capable of installing gravity sewers
or other types of pipelines to the required tolerances, for line and
grade.

[0011] Pipe Jacked: The pipeline is constructed by consecutively pushing
pipes and the MTBM through the ground using a jacking system for thrust.

[0012] Continuously supported: Continuous pressure is provided to the face
of the excavation to balance groundwater and earth pressures.

[0013] The above citations are inserted merely to acquaint the reader with
the fact that in the modem context it is possible to obtain rapid remote
controlled boring of pipe holes, so as to facilitate installation of pipe
suitable for such installation. The remainder of the "ice lens" approach
as herein stated are based upon the availability of such boring
technology.

[0014] No sophisticated explanation of the Rankine Cycle is attempted nor
necessary here, but a baseline discussion will speed appreciation for
those who have not seen their high school or college texts for a while.

[0015] It is understood that it takes energy to convert any type of matter
from its liquid state to its vapor state. Rather than getting esoteric,
just consider the tea kettle; the kettle and its contents are heated, the
boiling point is reached, at the boiling point the water reaches its
vapor state, and leaves the kettle. It almost immediately precipitates to
what we see as "steam," although close examination of the spout will show
a gap, perhaps we could call it a vapor gap, which is a view through the
transparent water in its true vapor state. That water in the vapor state
is invisible is known to those who have visited the engine rooms of steam
turbine aircraft carriers, where in olden days, when a leak was
suspected, a broomstick would be swung before a worker as he walked, as
the thin vapor stream would cut the stick in half, thereby saving the
man. Those turbines, of course, took immense amounts of fuel to operate,
originally fuel oil, later nuclear. Bottom line, to take a fluid to the
vapor state requires heat.

[0016] Our common experience may cause us to first visualize this as a
one-way street of analysis; we apply heat, the fluid eventually reaches
the boiling point as a result of the input of the heat, the heat having
forced sufficient molecular vibratory activity that the vapor state is
reached as a result of the heat. However, as Lord Kelvin taught, the
system is a two-way thoroughfare. That is why we have working
refrigerators. In that context, the evaporation cycle of a gas, chosen
for its low boiling point (an issue which will be shown as relevant to
the macro-machine here contemplated for radioactive containment) can,
through compression of that gas (thus the "compressor" of a refrigerator)
result in the use of the evaporative cycle, which is called the Rankine
Cycle, for the extraction of heat, through the forcing of the cycle by
compression of the vapor (gaseous state) so that the liquid state is
reached, and then the carefully controlled evaporation of the subject
liquid, thereby drawing heat at that point of conversion, from the
surrounding material world. These are well understood baseline concepts
with which all readers of this paper will have been familiar, but it is
suggested that a quick review will enhance appreciation of the
feasibility of the macro-application as hereafter explained.

[0017] These and many other objects and advantages of the present subject
matter will be readily apparent to one skilled in the art to which the
invention pertains from a perusal of the claims, the appended drawings,
and the following detailed description of preferred embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018]FIG. 1 is a top view of an embodiment of the present subject
matter.

[0019]FIG. 2 is a side view of an embodiment of the present subject
matter.

DETAILED DESCRIPTION

[0020] It is within existing engineering technology to create what amounts
to a macro-refrigerator through very carefully sited drilling of the
earth around the reactors suffering from meltdown, so as to create an
"ice basket" beneath the reactor cores involved. The formation of such an
ice lens, or basket in its fullest application, will result in diminished
levels of radioactive water reaching the sea. This is what can be done:

[0021] One embodiment to prevent such migration of contaminates is the
drilling of a multiple twined lateral tunnels beneath the affected
reactors. The tunnels, probably six twin bores, should be drilled, first,
down at a 45 or so degree angle (or such shallower angle as may be
necessary for pipe insertion), to then a level bore, at a drilled
position centered below each melting reactor.

[0022] For example to use an arbitrary figure of a thousand foot radius
from the center of the containment, may define an appropriate balance
between exposure avoidance needs and practical necessities relating to
the boring and pipe insertion process. Obviously, commencement of
operations from a threshold outside the ambit of severe cumulative
exposure risks would be wise, but at the edge, so as to minimize the
amount of drilling involved.

[0023] Preferably the boring should be a downward drilling on a 45 degree
angle, to, again, here for illustration, about one hundred feet below or
lower than the base of the reactor, or whatever is left of it as in the
case of an accident. The construction of the containment grid could also
be done preemptively during construction of the reactor or other source
of contaminates, or as a matter of course before any such emergency.

[0024] There may be a lateral portion. These lateral portions are well
within the capacity fairly commonly available robotic pipe insertion
drilling equipment as alluded to above. It is suggested that due to
various factors, multiple holes should be commenced as equipment and
staffing become available.

[0025] It is known that 24 inch micro-tunneling is available in industry.
For the instant illustrative purposes, it is envisioned using a 18 inch
pipe. There should be the insertion of insulated pipe through the
resulting tunnel. It is preferable to keep this as simple as possible.
There are means of cooling the frontal area of the insertion sans
pumping, but believed this to be a bit more complex than likely
justified.

[0026] Preferably there should be two twin pipes drilled, think of it as a
"double barreled" approach. This is necessary because the currently
escaping radioactive sea water is at or near sea level, and not solely at
lower elevations, though this will of course inevitably become a
deepening problem. The desirability for twin bores will be shortly
examined.

[0027] Upon the insertion of the insulated pipe, which at the least must
have telemetry for heat, there should be the insertion of a low boiling
point gas. Preferably liquid nitrogen. It is noted that while venting of
the nitrogen post use is likely, this need not involve any particulate
radiation. There is the need to control the post evaporation venting of
the gas, which can involve compression and reuse, however such is not the
focus, the focus here will be on cooling, and not re-circulation.

[0028] The baseline is that a cold non-explosive gas, here liquid nitrogen
may be inserted via a well-insulated interior casing, or pipe, which is
in turn inserted inside the pipe originally inserted into the bore. This
method mimics a repair method already in wide use for the repair of
deteriorated pipe via the insertion of a pipe of lesser dimension, which
in current sewer pipe repair scenarios is called "re-lining."

[0029] When spot repairs of old pipe lines, mainly sewers, are no longer
viable, local authorities are faced with the problem of rehabilitating or
replacing pipelines in the course of time. Replacement has the
disadvantage of being very costly and disruptive to urban areas where the
largest sewer networks are located.

[0030] HOBAS pipes are inserted in the existing pipeline with grout
cementing them in place. In view of the savings municipal authorities are
now allocating as much as 50% of budgets to rehabilitation. These types
of products are ideal for this application being lightweight, corrosion
resistant, quality-assured, easily jointed and rigid to resist grouting
forces.

[0031] It is noted that there are several indications at the HOBAS site of
the use of resins to obtain near-perfect interior smoothness, coupled
with entire leakage prevention, using modem materials. So long as the
bore can be made at a level sufficient that heat ruin of the piping
systems here contemplated is avoided (this may ultimately involve
"leapfrog" installations of the "pipe basket"), there may and should be
the capacity to entirely insulate the low boiling point gas (here,
nitrogen) from contact with radioactive fluid. This would result in a
clean vent, although the potential for compression and re-circulation (a
true "mega-fridge") is obvious.

[0032] In this contemplated system of twin, or paired, bores, each twin
bore will have a "nominal" end (where temperatures exterior to the
insulation are consistent with ambient OAT), and a "cold end" which will
be the area from the point of release just to the near side of bottom
dead center from the reactor. It is preferable that the point of N2
release be prior to the position in the pipe directly below bottom dead
center of the reactor, so that direct cooling from the N2 can come prior
to, or without, pipe insertion directly below the heat source. The
reasons for this will be fairly apparent thus no fuller explanation is
furthered here.

[0033] Thus, half the each pipe is "ambient," and half of each pipe, from
bottom dead center to the exterior gas release (or compression) point, is
very cold. This will cause ice to rime upon the pipe, and so long as gas
release is continued, cooling of the surrounding rock/water substrate to
occur, to the extent that ice will migrate out from the pipe. This is why
a twin bore is advantageous, since the result will be cooling all the way
from bottom dead center to the surface, with the insulated pipe having
been installed from opposing positions on the circle which defines the
drill origination circumference around the affected reactor(s). One such
installation, of just one twin pipe system, would, if well engineered,
result in some reduction of rate of radioactive water loss to the
environment, due to water viscosity increase and resulting reduction in
velocity of migration. Thus, a resulting "ice lens" beneath the affected
reactor.

[0034] However, the next set of twin pipe bores, each "fueled" in opposing
directions of super-cool liquid insertion, would commence the formation
not just of an "Ice Lens" but rather the building up of an ice web, or
"Ice Basket" should result. It would be essential to drill each
succeeding twin bore system to an elevation above or below all preceding
bores, so as to avoid one drilled system from ruining its predecessor.
These are matters of intricate field detail, but quite manageable for one
of skill in the art.

[0035] There are two methods of freezing involved. First, the liquid
nitrogen (the world's supply could if necessary be devoted to this, a
unifying effort, though I recognize that this as a melodramatic
statement) will, at the least, if there is continuation, cause a freezing
of the ground water, just because it is a super-cold liquid. However, it
will inevitably evaporate, also thus causing "heat drain" from the
Rankine process from the surrounding rock/water milieu. If this
groundwater freezing is thus brought to equilibrium with the heat output,
time will be bought. There are other applications, but there are problems
with loss of ductility at every turn. Still, a desperate situation may
sometimes only be surmounted through recognition of the need for an
inventive approach. As with some other suggestions, this is sent along
for reasons of citizenship. Rather than evaluating this, it is suggested
that it be forwarded and evaluated by others more formally qualified than
the undersigned.

[0036] FIGS. 1 and 2 illustrate the proposed drilling, and the results of
actuation of the system as herein described. This is a method through
which the leakage of radioactive water into the ocean can be reduced in
magnitude and stalled at such a reduced rate for a protracted period of
time.

[0037]FIG. 1 is a side view of an embodiment 100 showing a simple drawing
of a nuclear reactor 10 of a general type, the earth 28 upon which it is
situated, the water table 26, an inlet casing pipe 12, through which an
ultra-low boil point fluid is inserted within an insulated pipe 16, so
that, at aperture 18, vaporization of the gas 20 occurs. This results in
contact cooling of the soil proximate the cooling channels 24, from the
N2, or other chosen refrigerant itself, but also draws heat, from the
evaporative cooling process inherent in the involved vaporization. An ice
region 22 is thereby produced at the exterior of the casing. Care must be
taken to assure that the N2 or other suitable gas is utterly dry, to
avoid aperture contamination. Hydraulic process is noted as one possible
adjunct to insertion. As noted previously the channels may be formed
during the construction of the site and thus other techniques may be
available. The potential for capture at vent 14 is recognized, with
possible re-compression and delivery of the compressed liquid and gas to
the inlet 12 as discussed above. However release to the atmosphere is
acceptable if tight seam is obtained, infiltration of the contaminate is
avoided, in which case the N2 in the gaseous state would have no toxic
character, already being roughly 78% of the ambient air.

[0038]FIG. 2 is a top view of an embodiment 200 of the subject matter
illustrating the use of multiple non-intersecting pipes, separated by
differing but near depth levels, so that, post aperture 18, as to each
such pipe, there is cooling effect from the direct contact with the
super-cooled liquid form of the N2 (or other) involved, and to a greater
effect, continuing up pipe 24 (and in this instance down stream) the
vaporization draws heat into the N2, which is then exhausted 14. This
results in cooling of the surrounding water, the viscosity increase
resulting therefrom thereby slowing velocity, and thereby reducing
capacity for the carrying of particulate matter. In addition, with
precise modeling before the fact and precise calibration in execution,
the overlapping instances of evaporating cooling will cause an ice lens
22 formation below the reactor 10, which should migrate upwards in
accordance with the exhaust pipes and their associated cooling effect. A
partial ice lens 22 is shown in FIG. 2. It is noted that while these
drawings have tended to illustrate the placing of the aperture near
bottom dead center, it likely will work better towards ice lens formation
if the aperture point is directly below the first encountered edge from
the vantage point of the insulated pipe, so that there will be a
resulting four cold pipe confluence below the partial melt, so as to
assist in ice web propagation. To assist in evaporation, a vacuum may
also be created in the cooling channels. Temperature control would be
advantageous.

[0039] Multiple configurations of the cooling channels are envisioned in
defining the boundary of the containment area, such shapes may include
bowl shapes, saucer shapes, hyperbolic, parabolic, cylindrical or
rectangular shape.

[0040] Another aspect of the present subject matter is the uses of
throttling of the gas rather than evaporation. In such case a compressed
gas would be provided and then expanded through the aperture 18 into the
cooling channels 24 at a much lower pressure and temperature.

[0041] While preferred embodiments of the present invention have been
described, it is to be understood that the embodiments described are
illustrative only and that the scope of the invention is to be defined
solely by the appended claims when accorded a full range of equivalence,
many variations and modifications naturally occurring to those of skill
in the art from a perusal hereof.